Birthstones have fascinated humanity for centuries, not only for their aesthetic appeal but also for their symbolic and cultural significance. While most people are familiar with their own birthstone, few know which of these precious gems command the highest prices on the market. The value of a birthstone is determined by a combination of factors: rarity, color, clarity, carat weight, and historical or cultural prestige. In the world of gemology, certain stones stand out for their exceptional worth, with prices reaching into the millions of dollars per carat. This article delves into the most expensive birthstones, examining their properties, origins, and the reasons behind their astronomical market values.
When we think of expensive gemstones, diamonds often come to mind. However, the birthstone world presents a different hierarchy of value. Among the 12 months, several birthstones have emerged as particularly costly, with prices that often surpass even those of diamonds. The most expensive birthstones include alexandrite, ruby, sapphire, emerald, and tanzanite—each with its own unique story of formation, cultural symbolism, and gemological properties. These stones are not only prized for their beauty but also for their scarcity and the difficulty involved in mining and cutting them. Understanding the factors that influence their price can help collectors, investors, and jewelry enthusiasts make informed decisions when considering these rare and valuable gems.
This article explores the most expensive birthstones in detail, including their historical significance, geological properties, and current market values. We will also examine the key factors that contribute to their high price tags and provide practical advice on how to care for these precious gems.
History and Lore
The practice of associating gemstones with specific months of the year dates back to biblical times. In the Old Testament, it is mentioned that Moses crafted a breastplate for Aaron, the high priest, which featured twelve stones representing the twelve tribes of Israel. Over time, this tradition evolved into the modern concept of birthstones, where each month is linked to one or more specific gemstones. While the exact origins of this practice are unclear, it has become a global phenomenon, with different cultures adding their own interpretations and symbolic meanings.
In the 19th century, alexandrite was discovered in the Ural Mountains of Russia. Named after Czar Alexander II, who was born on the day of its discovery, this gemstone quickly became a symbol of Russian nobility. Its remarkable color-changing property—shifting from green in daylight to red under incandescent light—was seen as a marvel of nature. The stone’s association with imperial Russia added to its mystique and value, making it one of the most sought-after gems of its time.
Rubies have a long and storied history, often associated with power, passion, and protection. In ancient cultures, rubies were believed to possess the power of life, with their deep red color symbolizing blood and vitality. The most prized rubies, known for their "pigeon's blood" hue, have been mined in Myanmar (Burma) for centuries. These stones were highly valued by royalty and warriors alike, who believed they could ward off evil and bring good fortune.
Sapphires, particularly those with a rich blue color, have been revered since antiquity. They were often associated with wisdom, truth, and divine favor. In medieval Europe, sapphires were believed to protect the wearer from envy and harm. The most famous sapphires, such as those found in Kashmir, India, are known for their velvety blue color and exceptional clarity. These stones have adorned the crowns and jewelry of kings and queens throughout history, solidifying their status as symbols of royalty and virtue.
Emeralds, with their vibrant green color, have been prized since the time of the ancient Egyptians. Cleopatra, the last pharaoh of Egypt, was known for her love of emeralds and often wore them as a symbol of her power and wealth. The stone’s association with rebirth and fertility made it a favorite in many cultures. In the 16th century, the Spanish conquest of the Americas brought vast quantities of emeralds from Colombia to Europe, where they became highly coveted by the aristocracy.
Tanzanite is a relatively new gemstone, discovered in the 1960s in the Merelani Hills of Tanzania. Its unique blue-violet color and limited geographic origin have made it one of the most sought-after birthstones in recent decades. Named after the country of its discovery, tanzanite quickly gained popularity for its striking appearance and rarity. It is often associated with modern luxury and is considered a symbol of uniqueness and individuality.
Geological Formation and Sources
The value of a gemstone is deeply tied to its geological origins and the rarity of its deposits. The most expensive birthstones are often those that are found in only a few locations worldwide, making them exceptionally scarce.
Alexandrite is a variety of chrysoberyl, a mineral that forms under specific geological conditions. It is primarily found in the Ural Mountains of Russia, though smaller deposits have also been discovered in Brazil, Sri Lanka, and East Africa. The stone’s color-changing property is due to the presence of trace elements like chromium, which interact with light in a unique way. The Russian deposits, however, are considered the most significant historically, and stones from this region are highly prized for their quality.
Rubies are a type of corundum, an aluminum oxide mineral that forms under high-pressure and high-temperature conditions. The most valuable rubies come from Myanmar (Burma), particularly the Mogok region, which is known for producing stones with the coveted "pigeon's blood" color. Other sources include Vietnam, Thailand, and Sri Lanka, but Burmese rubies are considered the gold standard in the gem trade. The formation of rubies requires the presence of chromium, which gives the stone its red color, and the absence of iron, which can dull the hue.
Sapphires are also a variety of corundum, but they derive their blue color from trace amounts of titanium and iron. The finest blue sapphires are sourced from Kashmir, India, where they were mined in the late 19th and early 20th centuries. These stones are known for their velvety texture and cornflower blue color. Other significant sources include Myanmar, Sri Lanka, and Madagascar. Sapphires can also occur in other colors, such as pink, yellow, and green, but blue remains the most valuable.
Emeralds are a type of beryl, a mineral that forms in pegmatites and hydrothermal veins. The most prized emeralds come from Colombia, which is renowned for producing stones with a deep, vibrant green color. Colombian emeralds are often characterized by inclusions, which are referred to as "jardins" (gardens in French), and are considered part of the stone’s character. Other sources include Zambia, Brazil, and Afghanistan. The formation of emeralds requires the presence of chromium and vanadium, which impart the green color, and the stones are often treated to enhance their clarity.
Tanzanite is a variety of zoisite, a mineral that forms in metamorphic rocks. It is found exclusively in the Merelani Hills of Tanzania, making it one of the rarest gemstones in the world. The stone’s blue-violet color is caused by the presence of vanadium and heat treatment, which is commonly applied to enhance its color. The limited geographic distribution of tanzanite contributes significantly to its high value and desirability.
Gemological Properties
The gemological properties of the most expensive birthstones play a crucial role in determining their value. These properties include color, clarity, cut, carat weight, and hardness on the Mohs scale. Each stone has a unique set of characteristics that gemologists use to evaluate its quality and worth.
Alexandrite is known for its color-changing properties, which make it highly desirable. On the Mohs scale, it ranks at 8.5, making it quite durable. Its refractive index ranges from 1.74 to 1.78, and its chemical composition is Al₂BeO₄. The rarity of large, high-quality alexandrite stones contributes to its high price. Color change is the most important factor, with stones showing a dramatic shift from green to red being the most valuable.
Rubies have a hardness of 9 on the Mohs scale, making them one of the hardest gemstones after diamonds. Their refractive index is between 1.76 and 1.78. The most valuable rubies have a deep red color, often described as "pigeon blood," and a high degree of clarity. Inclusions are common in rubies, but stones with minimal inclusions command premium prices. The chemical formula for ruby is Al₂O₃, with chromium providing the red color.
Sapphires, like rubies, are corundum and have a hardness of 9. Their refractive index ranges from 1.76 to 1.77. The most prized blue sapphires have a medium to dark blue hue with a velvety texture. Clarity is important, but inclusions are often tolerated if they do not affect the stone’s brilliance. Sapphires can also exhibit asterism (a star-like effect) when cut en cabochon, which adds to their value.
Emeralds have a hardness of 7.5 to 8 on the Mohs scale, making them less durable than corundum but still suitable for jewelry. Their refractive index ranges from 1.57 to 1.58, and their chemical composition is Be₃Al₂(SiO₃)₆. Emeralds are known for their inclusions, which are often accepted as part of the stone’s character. The most valuable emeralds have a rich green color with good saturation and clarity. Treatment with oil or resin is common to enhance clarity, and untreated stones are significantly more valuable.
Tanzanite has a hardness of 6 to 6.5 on the Mohs scale, making it relatively soft and requiring careful handling. Its refractive index ranges from 1.69 to 1.70, and its chemical composition is Ca₂Al₃(SiO₄)₃(OH). The stone’s blue-violet color is its most defining feature, and stones with intense, saturated color are highly valued. Due to its softness, tanzanite is often used in earrings and pendants rather than rings, where it is less likely to be subjected to impact.
The following table summarizes the key gemological properties of the most expensive birthstones:
| Gemstone | Chemical Formula | Mohs Hardness | Refractive Index | Key Color Characteristics |
|---|---|---|---|---|
| Alexandrite | Al₂BeO₄ | 8.5 | 1.74 – 1.78 | Color-changing (green to red) |
| Ruby | Al₂O₃ | 9 | 1.76 – 1.78 | Deep red ("pigeon's blood") |
| Sapphire | Al₂O₃ | 9 | 1.76 – 1.77 | Blue (velvety texture) |
| Emerald | Be₃Al₂(SiO₃)₆ | 7.5 – 8 | 1.57 – 1.58 | Rich green (with inclusions) |
| Tanzanite | Ca₂Al₃(SiO₄)₃(OH) | 6 – 6.5 | 1.69 – 1.70 | Blue-violet |
Symbolism and Metaphysical Beliefs
Beyond their physical properties, the most expensive birthstones are rich in symbolism and metaphysical beliefs, which have been passed down through generations. These associations often enhance their value and appeal to collectors and enthusiasts.
Alexandrite is considered a stone of good omens and is believed to bring balance and harmony to the wearer. In Russian folklore, it was thought to possess the power to change one’s fortune, reflecting its own color-changing property. It is associated with the month of June and is said to enhance intuition and creativity.
Rubies are symbols of passion, love, and vitality. In many cultures, they are believed to protect the wearer from harm and attract prosperity. In Hindu tradition, rubies are associated with the sun and are thought to bring power and authority. The stone’s deep red color is linked to the heart and is often used in jewelry meant to symbolize deep emotional connections.
Sapphires are associated with wisdom, truth, and spiritual enlightenment. In medieval times, they were believed to protect against envy and attract divine favor. Sapphires are also linked to the month of September and are said to promote mental clarity and focus. Blue sapphires, in particular, are considered stones of communication and self-expression.
Emeralds symbolize rebirth, fertility, and eternal love. In ancient Egypt, they were associated with the goddess Isis and were believed to provide immortality. In modern metaphysical beliefs, emeralds are said to promote emotional balance and healing. They are the birthstone for May and are often given as a symbol of enduring love and commitment.
Tanzanite is associated with transformation and spiritual awakening. Its unique color is believed to stimulate the throat and third eye chakras, enhancing communication and intuition. As a relatively new gemstone, tanzanite is often linked to modern spirituality and personal growth. It is the birthstone for December and is thought to bring calm and clarity to the wearer.
Care and Cleaning
Proper care is essential to maintain the beauty and value of expensive birthstones. Each stone has specific requirements based on its hardness, cleavage, and sensitivity to heat or chemicals.
Alexandrite, with a hardness of 8.5, is relatively durable. It can be cleaned with warm, soapy water and a soft brush. However, it is important to avoid exposing it to high heat, as this can cause it to lose its color.
Rubies and sapphires, both with a hardness of 9, are highly durable. They can be cleaned with warm, soapy water and a soft brush or a diamond-specific cleaning solution. Avoid using harsh chemicals or abrasive materials, as these can damage the gemstone's surface.
Emeralds, with a hardness of 7.5 to 8, require more careful handling due to their inclusions and potential for cleavage. They should be cleaned with a soft cloth and mild soap, avoiding ultrasonic cleaners and steam, which can cause the stone to crack. It is also important to avoid exposing emeralds to high heat.
Tanzanite, with a hardness of 6 to 6.5, is the softest of the expensive birthstones and requires gentle care. It should be cleaned with a soft cloth and mild soap, and it is important to avoid exposure to high heat or direct sunlight, as this can cause it to fade. Due to its softness, tanzanite is best suited for jewelry that is not subjected to daily wear, such as earrings or pendants.
Diamonds, with a hardness of 10, are the most durable of all gemstones. They can be cleaned with warm, soapy water and a soft brush or a diamond-specific cleaning solution. However, it is important to avoid using harsh chemicals or abrasive materials, as these can damage the gemstone's surface.
Factors Influencing Price
The high price of these birthstones is influenced by a combination of factors, including rarity, color, clarity, carat weight, and market demand. Understanding these factors can help buyers and collectors make informed decisions.
Rarity is a primary driver of value. Alexandrite, for example, is extremely rare, especially in larger sizes. Its limited geographic distribution and unique color-changing property contribute to its high price. Similarly, tanzanite is found only in Tanzania, making it exceptionally scarce. Rubies and emeralds from specific locations, such as Burmese rubies and Colombian emeralds, are also highly prized due to their limited availability.
Color is another critical factor. The most valuable stones have intense, saturated colors. For rubies, the "pigeon's blood" red is the most sought after. For sapphires, a deep blue with a velvety texture is ideal. Emeralds with a vibrant green hue are highly valued, while tanzanite's blue-violet color is its defining feature. Alexandrite's color change is its most important attribute, with stones showing a dramatic shift being the most valuable.
Clarity also plays a significant role. While inclusions are common in many gemstones, stones with minimal inclusions are more valuable. However, in some cases, such as emeralds, inclusions are accepted as part of the stone’s character. A gemological lab certificate is essential for expensive stones, as it indicates whether the stone has been treated. Treated stones are 30-70% less expensive than untreated stones, and clarity treatments, such as oiling or resin filling, are common for emeralds.
Carat weight influences price, with larger stones being rarer and more expensive. However, the price per carat increases exponentially with size, especially for high-quality stones. For example, a large, high-quality ruby or emerald can command millions of dollars per carat.
Market demand and branding also affect prices. Diamonds, for instance, are highly valued due to global demand and marketing strategies, even though they are not the rarest gemstones. Colored diamonds, such as pink, blue, or green, can fetch prices exponentially higher than colorless diamonds. Similarly, the popularity of certain birthstones, like tanzanite, can drive up prices due to increased consumer interest.
Conclusion
The most expensive birthstones are not only prized for their beauty but also for their rarity, historical significance, and unique gemological properties. From the color-changing alexandrite to the deep red ruby and the velvety blue sapphire, each of these gemstones tells a story of natural wonder and human fascination. Understanding the factors that contribute to their high value—such as color, clarity, carat weight, and origin—can help collectors and enthusiasts appreciate these stones on a deeper level. Whether as an investment, a meaningful gift, or a personal treasure, these rare and valuable birthstones continue to captivate and inspire.